Critical Kush Barneys Farm 24 Days Old, Transplanted once from Red Beer Cups, fed 2 times 1ML of DNF Gro A & Gro B in the cups, 1 week ago, transplanted and fed plain water couple days ago, I plan on feeding 2.5 DNF A&B, I Havent really gave them that much food really.

The leafs are getting small brown spots, that give to what is pictured above.

Do I need Cal / Mag ?

I thought it might be the air being sucked out too fast and causing the air to be dry, temps are in the 70's with my big fans, and when i unhook my big fan the temps are 80's. Humitity is like 35%.

You didn't mention the medium. I use Roots potting soil and don't feed at all until flower. At 80 degrees, 35% is too low. Sounds like you have already figured out that your problem is likely to be a combination of too low humidity and too much nutrient. You might try placing a tray with a few inches of moist vermiculite under the pots to raise the humidity. It seems unlikely that you would have a Cal-Mag problem with plants this small.

The medium is Premium Potting Soil it says it has a small amount of fertilizer, (0.6 Nitrogen, and small amount of Potash) as perlite, black earth, lime.

I only added 1ml of grow to 1 gallon when they were in red cups, I transplanted and just fed water, I was planning on giving a proper nutreint 2.5 ml, when these pots dry out. I was thinking they might need food?

other than that I havent added anything in a week almost, disappointing when I dont know why im getting brown spots, that turn to dead growth, they are going on to 6 node now, should i feed a regular feeding of 2.5 ml gro a & B to 1 gallon or just use water again? they havent really got a good feeding unless there is enough already in the potting soil..

They would tell you if they needed to be fed by turning pale or spindly. Yours look fine except for the older, bottom leaves and that's where over fertilization shows up. In brief, salts accumulate in the tips and margins of older leaves, leading to leaf burn. Low humidity increases water loss through the tips and that means even more salt build up. The more salt build up, the more burn. Your new growth looks ok, so just water them and be patient.

yes , to add to what olekingkole says , if your soil is premium stuff, personally i really wouldnt add ANY feed until they are around 4-6 weeks old .... wait till 4 weeks then slowly add nutes ...Most people make the over feed mistake (I know i did) .. but then i witnessed an amazing thing that changed how i thought about nutes etc ..
i was making cuttings in the shed , it was summer .. i put a cutting in a container with water , then i inadvertently forgot about it and left it for about 25 days ... when i returned , the cutting had grown (albeit spindly) into a lovely plant , with nothing more than water and sunlight , no nutes , no soil , nothing , just water and sunlight ...
some plants guzzle 'N' like its going out of fashion while others can more or less do a whole grow with very little if any nutes , but as said , its better to react to the plant , than the plant react to the feed

Thanks for the replys, if a mod could delete that garbage post up there, that would be great!

You guys are right, I didnt read the bag, my last grow I switched soils to this brand, and didnt think much of it. When I got home I checked and read the bag, it is good soil, but has a fertilizer included that says to start a 20-20-20 after 1 month ! So, i really dont need to do anything but add water for the time being !

When I switch to flower, and repot into the last pot with this soil again should I just continue to water with no nutes, or should I do a very small bit of flower nutes.

The bag says it has 0.6 - 0 - 0.5 (good for 1 month before fertilization is required)

Thanks for the replys, I was able to figure it out with your replys and some research on google and soils.

I moved them to the 250 HPS last light to veg, I find the CFL's are good for seedling stage and cloning but very slow growth, they looked very happy under more light and warm temps, going to water tonight and do a small flush, post some pics in a few weeks of whats going on with the grow. Im excited to try this Critical Kush, I been reading its a good potent strain!

I recently ran a grow of critical kush from clone, unsure of exact strain, might have been from barneys originally I don't know. Lethal high, couch lock. Be very wary of bud rot, those colas get absolutely massive. Great yielder even after losing an oz or so per plant due to humidity problems.

Critical Kush Barneys Farm 24 Days Old, Transplanted once from Red Beer Cups, fed 2 times 1ML of DNF Gro A & Gro B in the cups, 1 week ago, transplanted and fed plain water couple days ago, I plan on feeding 2.5 DNF A&B, I Havent really gave them that much food really.

The leafs are getting small brown spots, that give to what is pictured above.

Do I need Cal / Mag ?

I thought it might be the air being sucked out too fast and causing the air to be dry, temps are in the 70's with my big fans, and when i unhook my big fan the temps are 80's. Humitity is like 35%.

Dude, could b wetness n soil?? It appears to b only on the edges so u might need some cal mag.... That herb looks fire tho bro!! I love how the leaves are all short n stout!! Looks like a monster n the making!'